Power diodes as are used, for example, in motor vehicle electronics, or generally in circuits comprising bridge drivers, are optimized with regard to their varied device parameters. In this context, it is desirable to strike a balance between different criteria or diode parameters. On the one hand, diodes having very good switch-off properties wherein the current does not snap in the reverse direction, but comes to an end softly so as to avoid induced voltage peaks and oscillations, but also diodes comprising sufficient surge current-carrying capacity are in demand. In the event of a surge current, a current more than ten times the nominal current of the diode may flow. In addition, the power losses occurring during operation of the diode are kept to a minimum. Switching operations on the power diodes and the power losses associated therewith may give rise to temperatures which may lead to a degradation or destruction of the device and the associated circuits.
Frequently, possibilities of optimizing the above-mentioned diode parameters entail disadvantages with regard to other diode parameters. For example, a gentle switch-off behavior of a diode may be achieved by suitable doping measures within the diode, which, however, frequently entails reduced surge current-carrying capacity of the device.
Therefore, what would be desirable is a semiconductor element for a power diode which comprises a high surge current-carrying capacity without entailing major drawbacks with regard to other important diode parameters, such as the switch-off behavior, the power losses or the forward voltage.